JPS6072705A - Manufacturing method of fiber-reinforced cement-based cured product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a fiber-reinforced cement-based cured product, such as a fiber-reinforced concrete IJ-cured product.

The purpose of this is to effectively orient reinforcing fibers in the stress direction, so that even if the cured product has a large cross section, it has a large reinforcing effect and can provide high tensile strength and bending strength. ).

carbon fiber, steel fiber or high tensile organic fiber,
Reinforcing fibers such as alkali-resistant glass fibers are used in concrete,
It can be mixed into cement slurry such as mortar to obtain a fiber-reinforced cement-based cured product. However, in the conventional manufacturing method in which reinforcing fibers are mixed into cement slurry and cast, the fibers are randomly oriented in three-dimensional space, reducing the reinforcing efficiency in the direction to be reinforced. According to Raurnaldl, when the fibers are oriented in a three-dimensional random state, the effective fiber length le3 is 1e, where the original fiber length is IO.
s=0.41 Jo. The effective fiber length le when this is oriented in a two-dimensional random state is = 0.64
It becomes 10.

The bending and tensile strength σC of FRC is as follows: α = constant including woven fiber dispersion coefficient, le - effective length of fiber, γf - adhesive stress of fiber D = fiber diameter, f = fiber mixing rate.

According to the above formula, if the effective fiber length le is increased, FR
The strength of C is improved. This can be understood from the fact that in conventional steel fiber reinforced concrete, the bending strength of spray-formed members is 1.3 to 1.5 times that of ordinary cast-formed members.

In addition, for example, if a cement slurry 3 mixed with reinforcing fibers 2 is poured into a formwork 1 and compacted using a vibrator 4 as shown in Fig. 1 to obtain a thick FRC, the slurry 3 Due to fluidization, the fibers 2 are oriented in the flow direction of the cis slurry (in the direction of the arrow in the drawing). Therefore, when the thickness of the molded member is large, defective portions 5 where the fibers 2 are oriented in the vertical direction are generated, and the reinforcing effect of the FRC in the lateral direction is reduced. For this reason, when using FRC with a large cross-sectional area, the reinforcing efficiency of the reinforcing fibers decreases, making it difficult to impart high bending strength and tensile strength.

This invention was made in view of the above circumstances.

The gist is that in the manufacturing method of fiber-reinforced cement-based hardened material (FRC) using cement-based slurry mixed with reinforcing fibers, the cement-based slurry is extruded from a slurry pump and molded, and the extruded layered surface and reinforcing fibers are formed. This method of manufacturing FRC is characterized in that the plane direction to be oriented is parallel to the direction of the plane, and the vertical dimension of the nozzle opening of the slurry pump is smaller than the fiber length of the reinforcing fibers.

In this manufacturing method, a cement slurry mixed with reinforcing fibers is extruded from a slurry pump in layers, and the vertical dimension of the nozzle opening is smaller than the length of the fibers. For this reason, the reinforcing fibers in the slurry discharged from the nozzle are corrected in orientation by the upper and lower edges of the nozzle, and are not oriented in the vertical direction, but are two-dimensionally oriented. Therefore, if the layered and extruded direction is parallel to the plane direction in which the reinforcing fibers of the desired FRC should be oriented, the reinforcing fibers of the obtained FRC can be two-dimensionally oriented in the desired plane direction, and the desired Increased bending and tensile strength can be achieved with directional reinforcement.

In addition, by stacking layered extrusions in the vertical direction or paralleling them in the horizontal direction, FRC with large thickness or width can be made.
The reinforcing fibers can be efficiently oriented in two dimensions and manufactured. Therefore, when the FRC obtained by this manufacturing method is made into a panel, for example, it has high bending strength and is extremely effective for use as a partition wall or the like. Further, even if the FRC has a large cross section, the reinforcing efficiency of the reinforcing fibers will not be reduced.

The method for manufacturing FRC according to the present invention will be explained below with reference to the drawings.

In FIG. 2, a cement slurry 3 mixed with reinforcing fibers 2 is extruded into a formwork 1 through an extrusion pipe 6 and a tip nozzle 7 of a cement slurry pump in a layered manner. The direction in which the layers are formed and extruded is parallel to the reinforcing direction of the obtained FRC, that is, the direction parallel to the plane in which the reinforcing fibers are two-dimensionally oriented. Further, the opening of the nozzle 7 has a rectangular shape, and its vertical dimension t is smaller than the fiber length of the reinforcing fiber.

The cement slurry 3 is in the form of layers, and is laid out in parallel on the plane of the formwork 1, and then layered in multiple layers to a predetermined thickness.
Mold RC. In order to maintain sufficient adhesion between each layer, compaction may be performed using a vibrator each time each layer is formed.

FIGS. 3(a) and 3(b) show the orientation direction of the reinforcing fibers 2 of the FRC molded as shown in FIG. 3, and the reinforcing fibers 2 are oriented within a two-dimensional plane in each layer. On the other hand, FRC using the conventional pouring method is shown in Fig. 4(a).
As shown in (b), the reinforcing fibers 2 have a three-dimensional orientation.

Table 1 shows the performance of FRC obtained by the method of this invention. This FRC is used as a reinforcing fiber with an average fiber length of 10 yn
FRC was manufactured using carbon fibers having a diameter of 17 μm and a cement-based slurry shown in Table 2. At this time, the shape of the nozzle opening of the slurry pump has a vertical dimension of 5mm, a lateral dimension of 15mm (1m rectangular cross section, and a predetermined member thickness of 1m).
FR is laminated in layers in the vertical direction 30 times until it becomes 50 mm.
C was molded.

Table 1 Bending strength of FRC * *Specimen dimensions 150XI 50X530 Loading method
As is clear from Table 2 and Table 1, the FR manufactured by this method
C has a bending strength of about 1 compared to that of conventional pour molding.
．． It can be seen that the effect of fiber reinforcement is 5 times greater.

The shape of the nozzle is not limited to a rectangular opening. For example, as shown in FIG. 5, valley-shaped incisions 8 may be made in the upper and lower edges of the opening to improve adhesion when layered extrudates are stacked in the vertical direction. Further, as shown in Fig. 6, the inside of the rectangular nozzle opening is divided into a plurality of sections in the width direction by vertical partition plates 9, each having a width t'.
The reinforcing fibers can also be oriented one-dimensionally in the extrusion direction when extruding cement-based slurry from a nozzle with the fiber length being smaller than the fiber length. Of course, in these cases, the vertical dimension t of the nozzle opening is smaller than or equal to the fiber length of the reinforcing fibers. In addition, multiple nozzles that satisfy the conditions of this manufacturing method,
It is also possible to form a layered extrudate by arranging them side by side in the horizontal and/or vertical directions and extruding the cement slurry from a plurality of nozzles at the same time to form a layered extrudate in parallel or stacked in the horizontal and/or vertical directions. .

The present invention is as described above, and this manufacturing method can efficiently orient reinforcing fibers in a desired direction and improve the bending strength and tensile strength of FRC. Further, even if the FRC has a large cross-sectional area, it has a high reinforcing effect without producing any defects.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are cross-sectional views showing the orientation state of reinforcing fibers before and after vibration in the casting method;
Figure 2 shows the extrusion of cement-based slurry using this manufacturing method.
FIG. 3 (a
), (b) and FIGS. 4(a) and (b) are a plan view and a cross-sectional view showing the orientation of reinforcing fibers in FRC manufactured by this manufacturing method and casting method, respectively, and FIG. 5 and FIG. FIG. 6 is an opening perspective view showing another embodiment of the nozzle. 1. Formwork, 2. Reinforcing fiber, 3. Cement slurry, 4. Vibrator, 5. Defect area, 6. Extruded pipe, 7.
・Nozzle, 8...notch, 9...partition plate. Figure 1 (a) (b) -(-111-Kaichi-ku. 加j jIInj[II]j 畔---11吻中城 " 0-

Claims (2)

[Claims] (1) In a method for producing a fiber-reinforced cement-based cured product using a cement-based slurry as a raw material mixed with reinforcing fibers, the cement-based slurry is extruded from a slurry pump and shaped,
and a method for producing a fiber-reinforced cement-based cured material, characterized in that the vertical dimension of the nozzle opening of the slurry pump is smaller than the fiber length of the reinforcing fibers. (2) The fiber-reinforced cement-based cured product according to claim 1, characterized in that the cement-based slurry is extruded in layers from a slurry pump and formed in layers in the vertical direction or in parallel in the horizontal direction. Manufacturing method.